1. Field of the Invention
The present invention relates to improvement in or relating to a photoelectric conversion device in which a plurality of semiconductor photoelectric conversion elements are sequentially arranged on a substrate in side-by-side relation and are connected in series.
The invention also pertains to a method for the manufacture of such a photoelectric conversion device.
2. Description of the Prior Art
Heretofore there has been proposed a photoelectric conversion device of the type wherein a plurality n (n being an integer greater than one) of semiconductor photoelectric conversion elements U.sub.1 to U.sub.n are sequentially formed side by side on a substrate having an insulating surface and are connected in series one after another.
According to this semiconductor photoelectric conversion device, the semiconductor photoelectric conversion element U.sub.i (i=1, 2, . . . n) has a first electrode E.sub.i formed on the substrate, a non-single-crystal semiconductor laminate member Q.sub.i formed on the first electrode E.sub.i and a second electrode F.sub.i formed on the non-single-crystal semiconductor laminate member Q.sub.i. The non-single-crystal semiconductor laminate member Q.sub.i has at least a first non-single-crystal semiconductor layer having a P or N conductivity type, a second non-single-crystal semiconductor layer having an I conductivity and a third non-single-crystal semiconductor layer having opposite conductivity type to the first non-single-crystal semiconductor layer. The first electrodes E.sub.j (j=1, 2, . . . (n-1)) and E.sub.j+1 are separated by a first groove G.sub.j. The non-single-crystal semiconductor laminate member Q.sub.j+1 extends to the non-single-crystal semiconductor laminate member Q.sub.j and down to the substrate in the groove G.sub.j. The second electrode F.sub.j+1 extends on the extending portion Q'.sub.j+1 of the non-single-crystal semiconductor laminate member Q.sub.j+1 and the non-single-crystal semiconductor laminate member Q.sub.j. The second electrodes F.sub.j and F.sub.j+1 are separated by an isolating portion H.sub.j opposite the first electrode E.sub.j. The non-single-crystal semiconductor laminate member Q.sub.j has a second groove O.sub.j extending between the first electrode E.sub.j and the second electrode F.sub.j+1. The second electrode F.sub.j+1 is coupled with the first electrode E.sub.j through a coupling portion K.sub.j formed by an extension of the second electrode F.sub.j+1 and extending into the second groove O.sub.j.
In such a photoelectric conversion device, leakage is likely to develop between the first electrodes E.sub.j and E.sub.j+1 across the extending portion Q.sub.j+1 ' of the non-single-crystal semiconductor laminate member Q.sub.j+1 ' of and between the second electrodes F.sub.j and F.sub.j+1 across the region of the non-single-crystal semiconductor laminate member Q.sub.j underlying the isolating portion H.sub.j.
The leakage between the first electrodes E.sub.j and E.sub.j+1 leads to a short circuit between the first electrode E.sub.j+1 and the second electrode F.sub.j+1 across the coupling portion K.sub.j, and the leakage between the second electrodes F.sub.j and F.sub.j+1 also leads to a short circuit between the first electrode E.sub.j and the second electrode F.sub.j across the coupling portion K.sub.j.
It is therefore impossible with the above conventional photoelectric conversion device to obtain a predetermined high voltage corresponding to the number n of photoelectric elements U.sub.1 to U.sub.n.
Furthermore, in the abovesaid conventional photoelectric conversion device, since a carrier depletion layer is not formed on the second non-single-crystal semiconductor layer of the laminate member Q.sub.i throughout it, all carriers which are created in the I-type second non-single-crystal semiconductor layer by the incidence of light on the laminate member Q.sub.i cannot effectively be field drifted to the P-type and/or N-type layer. Accordingly, the conventional photoelectric conversion device is relatively low in photoelectric conversion efficiency.